blob: 8c8c11afdb19a1ec17fc9619adce8442eaa95313 [file] [log] [blame]
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "crypto/hmac.h"
#include <openssl/hmac.h>
#include <stddef.h>
#include <algorithm>
#include <vector>
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/stl_util.h"
#include "crypto/openssl_util.h"
namespace crypto {
struct HMACPlatformData {
std::vector<unsigned char> key;
HMAC::HMAC(HashAlgorithm hash_alg) : hash_alg_(hash_alg) {
// Only SHA-1 and SHA-256 hash algorithms are supported now.
DCHECK(hash_alg_ == SHA1 || hash_alg_ == SHA256);
bool HMAC::Init(const unsigned char* key, size_t key_length) {
// Init must not be called more than once on the same HMAC object.
plat_.reset(new HMACPlatformData());
plat_->key.assign(key, key + key_length);
return true;
if (plat_) {
// Zero out key copy.
plat_->key.assign(plat_->key.size(), 0);
bool HMAC::Sign(const base::StringPiece& data,
unsigned char* digest,
size_t digest_length) const {
DCHECK(plat_); // Init must be called before Sign.
ScopedOpenSSLSafeSizeBuffer<EVP_MAX_MD_SIZE> result(digest, digest_length);
return !!::HMAC(hash_alg_ == SHA1 ? EVP_sha1() : EVP_sha256(),
plat_->, plat_->key.size(),
reinterpret_cast<const unsigned char*>(,
data.size(), result.safe_buffer(), NULL);
} // namespace crypto